ssl/d1_both.c

   1 /* ssl/d1_both.c */
   2 /*
   3  * DTLS implementation written by Nagendra Modadugu
   4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
   5  */
   6 /* ====================================================================
   7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright
  14  *    notice, this list of conditions and the following disclaimer.
  15  *
  16  * 2. Redistributions in binary form must reproduce the above copyright
  17  *    notice, this list of conditions and the following disclaimer in
  18  *    the documentation and/or other materials provided with the
  19  *    distribution.
  20  *
  21  * 3. All advertising materials mentioning features or use of this
  22  *    software must display the following acknowledgment:
  23  *    "This product includes software developed by the OpenSSL Project
  24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  25  *
  26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  27  *    endorse or promote products derived from this software without
  28  *    prior written permission. For written permission, please contact
  29  *    openssl-core@openssl.org.
  30  *
  31  * 5. Products derived from this software may not be called "OpenSSL"
  32  *    nor may "OpenSSL" appear in their names without prior written
  33  *    permission of the OpenSSL Project.
  34  *
  35  * 6. Redistributions of any form whatsoever must retain the following
  36  *    acknowledgment:
  37  *    "This product includes software developed by the OpenSSL Project
  38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  39  *
  40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  51  * OF THE POSSIBILITY OF SUCH DAMAGE.
  52  * ====================================================================
  53  *
  54  * This product includes cryptographic software written by Eric Young
  55  * (eay@cryptsoft.com).  This product includes software written by Tim
  56  * Hudson (tjh@cryptsoft.com).
  57  *
  58  */
  59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  60  * All rights reserved.
  61  *
  62  * This package is an SSL implementation written
  63  * by Eric Young (eay@cryptsoft.com).
  64  * The implementation was written so as to conform with Netscapes SSL.
  65  *
  66  * This library is free for commercial and non-commercial use as long as
  67  * the following conditions are aheared to.  The following conditions
  68  * apply to all code found in this distribution, be it the RC4, RSA,
  69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  70  * included with this distribution is covered by the same copyright terms
  71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  72  *
  73  * Copyright remains Eric Young's, and as such any Copyright notices in
  74  * the code are not to be removed.
  75  * If this package is used in a product, Eric Young should be given attribution
  76  * as the author of the parts of the library used.
  77  * This can be in the form of a textual message at program startup or
  78  * in documentation (online or textual) provided with the package.
  79  *
  80  * Redistribution and use in source and binary forms, with or without
  81  * modification, are permitted provided that the following conditions
  82  * are met:
  83  * 1. Redistributions of source code must retain the copyright
  84  *    notice, this list of conditions and the following disclaimer.
  85  * 2. Redistributions in binary form must reproduce the above copyright
  86  *    notice, this list of conditions and the following disclaimer in the
  87  *    documentation and/or other materials provided with the distribution.
  88  * 3. All advertising materials mentioning features or use of this software
  89  *    must display the following acknowledgement:
  90  *    "This product includes cryptographic software written by
  91  *     Eric Young (eay@cryptsoft.com)"
  92  *    The word 'cryptographic' can be left out if the rouines from the library
  93  *    being used are not cryptographic related :-).
  94  * 4. If you include any Windows specific code (or a derivative thereof) from
  95  *    the apps directory (application code) you must include an acknowledgement:
  96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  97  *
  98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 108  * SUCH DAMAGE.
 109  *
 110  * The licence and distribution terms for any publically available version or
 111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
 112  * copied and put under another distribution licence
 113  * [including the GNU Public Licence.]
 114  */
 115
 116 #include <limits.h>
 117 #include <string.h>
 118 #include <stdio.h>
 119 #include "ssl_locl.h"
 120 #include <openssl/buffer.h>
 121 #include <openssl/rand.h>
 122 #include <openssl/objects.h>
 123 #include <openssl/evp.h>
 124 #include <openssl/x509.h>
 125
 126
 127 /* XDTLS:  figure out the right values */
 128 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
 129
 130 static unsigned int dtls1_min_mtu(void);
 131 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
 132 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
 133         unsigned long frag_len);
 134 static unsigned char *dtls1_write_message_header(SSL *s,
 135         unsigned char *p);
 136 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
 137         unsigned long len, unsigned short seq_num, unsigned long frag_off,
 138         unsigned long frag_len);
 139 static int dtls1_retransmit_buffered_messages(SSL *s);
 140 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
 141     long max, int *ok);
 142 static void dtls1_process_handshake_fragment(SSL *s, int frag_len);
 143
 144 static hm_fragment *
 145 dtls1_hm_fragment_new(unsigned long frag_len)
 146     {
 147     hm_fragment *frag = NULL;
 148     unsigned char *buf = NULL;
 149
 150     frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
 151     if ( frag == NULL)
 152         return NULL;
 153
 154     buf = (unsigned char *)OPENSSL_malloc(frag_len
 155         + DTLS1_HM_HEADER_LENGTH);
 156     if ( buf == NULL)
 157         {
 158         OPENSSL_free(frag);
 159         return NULL;
 160         }
 161
 162     frag->fragment = buf;
 163
 164     return frag;
 165     }
 166
 167 static void
 168 dtls1_hm_fragment_free(hm_fragment *frag)
 169     {
 170     OPENSSL_free(frag->fragment);
 171     OPENSSL_free(frag);
 172     }
 173
 174 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
 175 int dtls1_do_write(SSL *s, int type)
 176         {
 177         int ret;
 178         int curr_mtu;
 179         unsigned int len, frag_off;
 180
 181         /* AHA!  Figure out the MTU, and stick to the right size */
 182         if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
 183         {
 184                 s->d1->mtu =
 185                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 186
 187                 /* I've seen the kernel return bogus numbers when it doesn't know
 188                  * (initial write), so just make sure we have a reasonable number */
 189                 if ( s->d1->mtu < dtls1_min_mtu())
 190                         {
 191                         s->d1->mtu = 0;
 192                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
 193                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
 194                                 s->d1->mtu, NULL);
 195                         }
 196                 }
 197 #if 0
 198         mtu = s->d1->mtu;
 199
 200         fprintf(stderr, "using MTU = %d\n", mtu);
 201
 202         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 203
 204         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
 205
 206         if ( curr_mtu > 0)
 207                 mtu = curr_mtu;
 208         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
 209                 return ret;
 210
 211         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
 212                 {
 213                 ret = BIO_flush(SSL_get_wbio(s));
 214                 if ( ret <= 0)
 215                         return ret;
 216                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
 217                 }
 218
 219         OPENSSL_assert(mtu > 0);  /* should have something reasonable now */
 220
 221 #endif
 222
 223         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
 224                 OPENSSL_assert(s->init_num ==
 225                         s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
 226
 227         frag_off = 0;
 228         while( s->init_num)
 229                 {
 230                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
 231                         DTLS1_RT_HEADER_LENGTH;
 232
 233                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
 234                         {
 235                         /* grr.. we could get an error if MTU picked was wrong */
 236                         ret = BIO_flush(SSL_get_wbio(s));
 237                         if ( ret <= 0)
 238                                 return ret;
 239                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH;
 240                         }
 241
 242                 if ( s->init_num > curr_mtu)
 243                         len = curr_mtu;
 244                 else
 245                         len = s->init_num;
 246
 247
 248                 /* XDTLS: this function is too long.  split out the CCS part */
 249                 if ( type == SSL3_RT_HANDSHAKE)
 250                         {
 251                         if ( s->init_off != 0)
 252                                 {
 253                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
 254                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
 255                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
 256
 257                 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
 258                                 if ( len <= DTLS1_HM_HEADER_LENGTH)
 259                                         len += DTLS1_HM_HEADER_LENGTH;
 260                                 }
 261
 262                         dtls1_fix_message_header(s, frag_off,
 263                                 len - DTLS1_HM_HEADER_LENGTH);
 264
 265                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
 266
 267                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
 268                         }
 269
 270                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
 271                         len);
 272                 if (ret < 0)
 273                         {
 274                         /* might need to update MTU here, but we don't know
 275                          * which previous packet caused the failure -- so can't
 276                          * really retransmit anything.  continue as if everything
 277                          * is fine and wait for an alert to handle the
 278                          * retransmit
 279                          */
 280                         if ( BIO_ctrl(SSL_get_wbio(s),
 281                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL))
 282                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
 283                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
 284                         else
 285                                 return(-1);
 286                         }
 287                 else
 288                         {
 289
 290                         /* bad if this assert fails, only part of the handshake
 291                          * message got sent.  but why would this happen? */
 292                         OPENSSL_assert(len == ret);
 293
 294                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
 295                                 /* should not be done for 'Hello Request's, but in that case
 296                                  * we'll ignore the result anyway */
 297                                 ssl3_finish_mac(s,
 298                                         (unsigned char *)&s->init_buf->data[s->init_off +
 299                                                 DTLS1_HM_HEADER_LENGTH], ret - DTLS1_HM_HEADER_LENGTH);
 300
 301                         if (ret == s->init_num)
 302                                 {
 303                                 if (s->msg_callback)
 304                                         s->msg_callback(1, s->version, type, s->init_buf->data,
 305                                                 (size_t)(s->init_off + s->init_num), s,
 306                                                 s->msg_callback_arg);
 307
 308                                 s->init_off = 0;  /* done writing this message */
 309                                 s->init_num = 0;
 310
 311                                 return(1);
 312                                 }
 313                         s->init_off+=ret;
 314                         s->init_num-=ret;
 315                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
 316                         }
 317                 }
 318         return(0);
 319         }
 320
 321
 322 /* Obtain handshake message of message type 'mt' (any if mt == -1),
 323  * maximum acceptable body length 'max'.
 324  * Read an entire handshake message.  Handshake messages arrive in
 325  * fragments.
 326  */
 327 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
 328         {
 329         int i, al;
 330
 331         /* s3->tmp is used to store messages that are unexpected, caused
 332          * by the absence of an optional handshake message */
 333         if (s->s3->tmp.reuse_message)
 334                 {
 335                 s->s3->tmp.reuse_message=0;
 336                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
 337                         {
 338                         al=SSL_AD_UNEXPECTED_MESSAGE;
 339                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
 340                         goto f_err;
 341                         }
 342                 *ok=1;
 343                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 344                 s->init_num = (int)s->s3->tmp.message_size;
 345                 return s->init_num;
 346                 }
 347
 348         do
 349                 {
 350                 if ( s->d1->r_msg_hdr.frag_off == 0)
 351                         {
 352                         /* s->d1->r_message_header.msg_len = 0; */
 353                         memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
 354                         }
 355
 356                 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
 357                 if ( i == DTLS1_HM_BAD_FRAGMENT ||
 358             i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
 359                         continue;
 360                 else if ( i <= 0 && !*ok)
 361                         return i;
 362
 363                 if (s->d1->r_msg_hdr.msg_len == s->init_num - DTLS1_HM_HEADER_LENGTH)
 364                         {
 365                         memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
 366
 367                         s->d1->handshake_read_seq++;
 368                         /* we just read a handshake message from the other side:
 369                          * this means that we don't need to retransmit of the
 370                          * buffered messages.
 371                          * XDTLS: may be able clear out this
 372                          * buffer a little sooner (i.e if an out-of-order
 373                          * handshake message/record is received at the record
 374                          * layer.
 375                          * XDTLS: exception is that the server needs to
 376                          * know that change cipher spec and finished messages
 377                          * have been received by the client before clearing this
 378                          * buffer.  this can simply be done by waiting for the
 379                          * first data  segment, but is there a better way?  */
 380                         dtls1_clear_record_buffer(s);
 381
 382             s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 383                         return s->init_num - DTLS1_HM_HEADER_LENGTH;
 384                         }
 385                 else
 386                         s->d1->r_msg_hdr.frag_off = i;
 387                 } while(1) ;
 388
 389 f_err:
 390         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 391         *ok = 0;
 392         return -1;
 393         }
 394
 395
 396 static int
 397 dtls1_retrieve_buffered_fragment(SSL *s, unsigned long *copied)
 398     {
 399     /* (0) check whether the desired fragment is available
 400      * if so:
 401      * (1) copy over the fragment to s->init_buf->data[]
 402      * (2) update s->init_num
 403      */
 404     pitem *item;
 405     hm_fragment *frag;
 406     unsigned long overlap;
 407     unsigned char *p;
 408
 409     item = pqueue_peek(s->d1->buffered_messages);
 410     if ( item == NULL)
 411         return 0;
 412
 413     frag = (hm_fragment *)item->data;
 414
 415     if ( s->d1->handshake_read_seq == frag->msg_header.seq &&
 416         frag->msg_header.frag_off <= s->init_num - DTLS1_HM_HEADER_LENGTH)
 417         {
 418         pqueue_pop(s->d1->buffered_messages);
 419         overlap = s->init_num - DTLS1_HM_HEADER_LENGTH
 420             - frag->msg_header.frag_off;
 421
 422         p = frag->fragment;
 423
 424         memcpy(&s->init_buf->data[s->init_num],
 425             p + DTLS1_HM_HEADER_LENGTH + overlap,
 426             frag->msg_header.frag_len - overlap);
 427
 428         OPENSSL_free(frag->fragment);
 429         OPENSSL_free(frag);
 430         pitem_free(item);
 431
 432         *copied = frag->msg_header.frag_len - overlap;
 433         return *copied;
 434         }
 435     else
 436         return 0;
 437     }
 438
 439
 440 static int
 441 dtls1_buffer_handshake_fragment(SSL *s, struct hm_header_st* msg_hdr)
 442 {
 443     hm_fragment *frag = NULL;
 444     pitem *item = NULL;
 445
 446     frag = dtls1_hm_fragment_new(msg_hdr->frag_len);
 447     if ( frag == NULL)
 448         goto err;
 449
 450     memcpy(frag->fragment, &(s->init_buf->data[s->init_num]),
 451         msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH);
 452
 453     memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
 454
 455     item = pitem_new(msg_hdr->seq, frag);
 456     if ( item == NULL)
 457         goto err;
 458
 459     pqueue_insert(s->d1->buffered_messages, item);
 460     return 1;
 461
 462 err:
 463     if ( frag != NULL) dtls1_hm_fragment_free(frag);
 464     if ( item != NULL) OPENSSL_free(item);
 465     return 0;
 466 }
 467
 468
 469 static void
 470 dtls1_process_handshake_fragment(SSL *s, int frag_len)
 471     {
 472     unsigned char *p;
 473
 474     p = (unsigned char *)s->init_buf->data;
 475
 476         ssl3_finish_mac(s, &p[s->init_num - frag_len], frag_len);
 477     }
 478
 479
 480 static int
 481 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st *msg_hdr, int *ok)
 482     {
 483     int i;
 484     unsigned char *p;
 485
 486     /* make sure there's enough room to read this fragment */
 487     if ( (int)msg_hdr->frag_len && !BUF_MEM_grow_clean(s->init_buf,
 488              (int)msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH + s->init_num))
 489         {
 490         SSLerr(SSL_F_DTLS1_PROCESS_OUT_OF_SEQ_MESSAGE,ERR_R_BUF_LIB);
 491         goto err;
 492         }
 493
 494     p = (unsigned char *)s->init_buf->data;
 495
 496     /* read the body of the fragment (header has already been read */
 497     if ( msg_hdr->frag_len > 0)
 498                 {
 499                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 500             &p[s->init_num],
 501             msg_hdr->frag_len,0);
 502                 if (i <= 0)
 503                         {
 504                         *ok = 0;
 505                         return i;
 506                         }
 507                 }
 508
 509     if ( msg_hdr->seq > s->d1->handshake_read_seq)
 510         dtls1_buffer_handshake_fragment(s, msg_hdr);
 511     else
 512         OPENSSL_assert(msg_hdr->seq < s->d1->handshake_read_seq);
 513
 514     return DTLS1_HM_FRAGMENT_RETRY;
 515 err:
 516     *ok = 0;
 517     return -1;
 518     }
 519
 520
 521 static long
 522 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
 523         {
 524         unsigned char *p;
 525         unsigned long l, frag_off, frag_len;
 526         int i,al;
 527         struct hm_header_st msg_hdr;
 528     unsigned long overlap;
 529
 530     /* see if we have the required fragment already */
 531     if (dtls1_retrieve_buffered_fragment(s, &l))
 532     {
 533         /* compute MAC, remove fragment headers */
 534         dtls1_process_handshake_fragment(s, l);
 535         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
 536         s->state = stn;
 537         return 1;
 538     }
 539
 540     /* get a handshake fragment from the record layer */
 541         p = (unsigned char *)s->init_buf->data;
 542
 543     /* read handshake message header */
 544         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],
 545                 DTLS1_HM_HEADER_LENGTH, 0);
 546         if (i <= 0)     /* nbio, or an error */
 547                 {
 548                 s->rwstate=SSL_READING;
 549                 *ok = 0;
 550                 return i;
 551                 }
 552
 553         OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
 554
 555         p += s->init_num;
 556     /* parse the message fragment header */
 557
 558     dtls1_get_message_header(p, &msg_hdr);
 559
 560     /*
 561      * if this is a future (or stale) message it gets buffered
 562      * (or dropped)--no further processing at this time
 563      */
 564     if ( msg_hdr.seq != s->d1->handshake_read_seq)
 565         return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
 566
 567     l = msg_hdr.msg_len;
 568     frag_off = msg_hdr.frag_off;
 569         frag_len = msg_hdr.frag_len;
 570
 571     /* sanity checking */
 572     if ( frag_off + frag_len > l)
 573         {
 574         al=SSL_AD_ILLEGAL_PARAMETER;
 575         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 576         goto f_err;
 577         }
 578
 579         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
 580         p[0] == SSL3_MT_HELLO_REQUEST)
 581         {
 582         /* The server may always send 'Hello Request' messages --
 583          * we are doing a handshake anyway now, so ignore them
 584          * if their format is correct. Does not count for
 585          * 'Finished' MAC. */
 586         if (p[1] == 0 && p[2] == 0 &&p[3] == 0)
 587             {
 588             if (s->msg_callback)
 589                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
 590                     p, DTLS1_HM_HEADER_LENGTH, s,
 591                     s->msg_callback_arg);
 592
 593             s->init_num = 0;
 594             return dtls1_get_message_fragment(s, st1, stn,
 595                 max, ok);
 596             }
 597         else /* Incorrectly formated Hello request */
 598             {
 599             al=SSL_AD_UNEXPECTED_MESSAGE;
 600             SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
 601             goto f_err;
 602             }
 603         }
 604
 605     /* XDTLS: do a sanity check on the fragment */
 606
 607     s->init_num += i;
 608
 609         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
 610                 {
 611                 /* BUF_MEM_grow takes an 'int' parameter */
 612                 if (l > (INT_MAX-DTLS1_HM_HEADER_LENGTH))
 613                         {
 614                         al=SSL_AD_ILLEGAL_PARAMETER;
 615                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 616                         goto f_err;
 617                         }
 618                 if (l && !BUF_MEM_grow_clean(s->init_buf,(int)l
 619                         + DTLS1_HM_HEADER_LENGTH))
 620                         {
 621                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
 622                         goto err;
 623                         }
 624         /* Only do this test when we're reading the expected message.
 625          * Stale messages will be dropped and future messages will be buffered */
 626         if ( l > (unsigned long)max)
 627                         {
 628                         al=SSL_AD_ILLEGAL_PARAMETER;
 629                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 630                         goto f_err;
 631                         }
 632
 633                 s->s3->tmp.message_size=l;
 634                 }
 635
 636     if ( frag_len > (unsigned long)max)
 637         {
 638         al=SSL_AD_ILLEGAL_PARAMETER;
 639         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 640         goto f_err;
 641         }
 642     if ( frag_len + s->init_num > (INT_MAX - DTLS1_HM_HEADER_LENGTH))
 643         {
 644         al=SSL_AD_ILLEGAL_PARAMETER;
 645         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
 646         goto f_err;
 647         }
 648
 649     if ( frag_len & !BUF_MEM_grow_clean(s->init_buf, (int)frag_len
 650              + DTLS1_HM_HEADER_LENGTH + s->init_num))
 651         {
 652         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
 653         goto err;
 654         }
 655
 656         if ( s->d1->r_msg_hdr.frag_off == 0)
 657                 {
 658                 s->s3->tmp.message_type = msg_hdr.type;
 659                 s->d1->r_msg_hdr.type = msg_hdr.type;
 660                 s->d1->r_msg_hdr.msg_len = l;
 661                 /* s->d1->r_msg_hdr.seq = seq_num; */
 662                 }
 663
 664         /* XDTLS:  ressurect this when restart is in place */
 665         s->state=stn;
 666
 667         /* next state (stn) */
 668         p = (unsigned char *)s->init_buf->data;
 669
 670         if ( frag_len > 0)
 671                 {
 672                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
 673             &p[s->init_num],
 674             frag_len,0);
 675         /* XDTLS:  fix this--message fragments cannot span multiple packets */
 676                 if (i <= 0)
 677                         {
 678                         s->rwstate=SSL_READING;
 679                         *ok = 0;
 680                         return i;
 681                         }
 682                 }
 683         else
 684                 i = 0;
 685
 686     /* XDTLS:  an incorrectly formatted fragment should cause the
 687      * handshake to fail */
 688         OPENSSL_assert(i == frag_len);
 689
 690 #if 0
 691     /* Successfully read a fragment.
 692      * It may be (1) out of order, or
 693      *           (2) it's a repeat, in which case we dump it
 694      *           (3) the one we are expecting next (maybe with overlap)
 695      * If it is next one, it may overlap with previously read bytes
 696      */
 697
 698     /* case (1): buffer the future fragment
 699      * (we can treat fragments from a future message the same
 700      * as future fragments from the message being currently read, since
 701      * they are sematically simply out of order.
 702      */
 703     if ( msg_hdr.seq > s->d1->handshake_read_seq ||
 704         frag_off > s->init_num - DTLS1_HM_HEADER_LENGTH)
 705     {
 706         dtls1_buffer_handshake_fragment(s, &msg_hdr);
 707         return DTLS1_HM_FRAGMENT_RETRY;
 708     }
 709
 710     /* case (2):  drop the entire fragment, and try again */
 711     if ( msg_hdr.seq < s->d1->handshake_read_seq ||
 712         frag_off + frag_len < s->init_num - DTLS1_HM_HEADER_LENGTH)
 713         {
 714         s->init_num -= DTLS1_HM_HEADER_LENGTH;
 715         return DTLS1_HM_FRAGMENT_RETRY;
 716         }
 717 #endif
 718
 719     /* case (3): received a immediately useful fragment.  Determine the
 720      * possible overlap and copy the fragment.
 721      */
 722     overlap = (s->init_num - DTLS1_HM_HEADER_LENGTH) - frag_off;
 723
 724     /* retain the header for the first fragment */
 725     if ( s->init_num > DTLS1_HM_HEADER_LENGTH)
 726         {
 727         memmove(&(s->init_buf->data[s->init_num]),
 728             &(s->init_buf->data[s->init_num + DTLS1_HM_HEADER_LENGTH + overlap]),
 729             frag_len - overlap);
 730
 731         s->init_num += frag_len - overlap;
 732         }
 733     else
 734         s->init_num += frag_len;
 735
 736     dtls1_process_handshake_fragment(s, frag_len - overlap);
 737
 738         if (s->msg_callback)
 739                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
 740                         (size_t)s->init_num, s,
 741                         s->msg_callback_arg);
 742         *ok=1;
 743
 744         return s->init_num;
 745
 746 f_err:
 747         ssl3_send_alert(s,SSL3_AL_FATAL,al);
 748     s->init_num = 0;
 749 err:
 750         *ok=0;
 751         return(-1);
 752         }
 753
 754 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
 755         {
 756         unsigned char *p,*d;
 757         int i;
 758         unsigned long l;
 759
 760         if (s->state == a)
 761                 {
 762                 d=(unsigned char *)s->init_buf->data;
 763                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
 764
 765                 i=s->method->ssl3_enc->final_finish_mac(s,
 766                         &(s->s3->finish_dgst1),
 767                         &(s->s3->finish_dgst2),
 768                         sender,slen,s->s3->tmp.finish_md);
 769                 s->s3->tmp.finish_md_len = i;
 770                 memcpy(p, s->s3->tmp.finish_md, i);
 771                 p+=i;
 772                 l=i;
 773
 774 #ifdef OPENSSL_SYS_WIN16
 775                 /* MSVC 1.5 does not clear the top bytes of the word unless
 776                  * I do this.
 777                  */
 778                 l&=0xffff;
 779 #endif
 780
 781                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
 782                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
 783                 s->init_off=0;
 784
 785                 /* buffer the message to handle re-xmits */
 786                 dtls1_buffer_message(s, 0);
 787
 788                 s->state=b;
 789                 }
 790
 791         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
 792         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
 793         }
 794
 795 /* for these 2 messages, we need to
 796  * ssl->enc_read_ctx                    re-init
 797  * ssl->s3->read_sequence               zero
 798  * ssl->s3->read_mac_secret             re-init
 799  * ssl->session->read_sym_enc           assign
 800  * ssl->session->read_compression       assign
 801  * ssl->session->read_hash              assign
 802  */
 803 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
 804         {
 805         unsigned char *p;
 806
 807         if (s->state == a)
 808                 {
 809                 p=(unsigned char *)s->init_buf->data;
 810                 *p++=SSL3_MT_CCS;
 811                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
 812                 s->d1->next_handshake_write_seq++;
 813                 s2n(s->d1->handshake_write_seq,p);
 814
 815                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
 816                 s->init_off=0;
 817
 818                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
 819                         s->d1->handshake_write_seq, 0, 0);
 820
 821                 /* buffer the message to handle re-xmits */
 822                 dtls1_buffer_message(s, 1);
 823
 824                 s->state=b;
 825                 }
 826
 827         /* SSL3_ST_CW_CHANGE_B */
 828         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
 829         }
 830
 831 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
 832         {
 833         unsigned char *p;
 834         int n,i;
 835         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
 836         BUF_MEM *buf;
 837         X509_STORE_CTX xs_ctx;
 838         X509_OBJECT obj;
 839
 840         /* TLSv1 sends a chain with nothing in it, instead of an alert */
 841         buf=s->init_buf;
 842         if (!BUF_MEM_grow_clean(buf,10))
 843                 {
 844                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
 845                 return(0);
 846                 }
 847         if (x != NULL)
 848                 {
 849                 if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
 850                         {
 851                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
 852                         return(0);
 853                         }
 854
 855                 for (;;)
 856                         {
 857                         n=i2d_X509(x,NULL);
 858                         if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
 859                                 {
 860                                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
 861                                 return(0);
 862                                 }
 863                         p=(unsigned char *)&(buf->data[l]);
 864                         l2n3(n,p);
 865                         i2d_X509(x,&p);
 866                         l+=n+3;
 867                         if (X509_NAME_cmp(X509_get_subject_name(x),
 868                                 X509_get_issuer_name(x)) == 0) break;
 869
 870                         i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
 871                                 X509_get_issuer_name(x),&obj);
 872                         if (i <= 0) break;
 873                         x=obj.data.x509;
 874                         /* Count is one too high since the X509_STORE_get uped the
 875                          * ref count */
 876                         X509_free(x);
 877                         }
 878
 879                 X509_STORE_CTX_cleanup(&xs_ctx);
 880                 }
 881
 882         /* Thawte special :-) */
 883         if (s->ctx->extra_certs != NULL)
 884         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
 885                 {
 886                 x=sk_X509_value(s->ctx->extra_certs,i);
 887                 n=i2d_X509(x,NULL);
 888                 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
 889                         {
 890                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
 891                         return(0);
 892                         }
 893                 p=(unsigned char *)&(buf->data[l]);
 894                 l2n3(n,p);
 895                 i2d_X509(x,&p);
 896                 l+=n+3;
 897                 }
 898
 899         l-= (3 + DTLS1_HM_HEADER_LENGTH);
 900
 901         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
 902         l2n3(l,p);
 903         l+=3;
 904         p=(unsigned char *)&(buf->data[0]);
 905         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
 906
 907         l+=DTLS1_HM_HEADER_LENGTH;
 908         return(l);
 909         }
 910
 911 int dtls1_read_failed(SSL *s, int code)
 912     {
 913     DTLS1_STATE *state;
 914     BIO *bio;
 915     int send_alert = 0;
 916
 917     if ( code > 0)
 918         {
 919         fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
 920         return 1;
 921         }
 922
 923     bio = SSL_get_rbio(s);
 924     if ( ! BIO_dgram_recv_timedout(bio))
 925         {
 926         /* not a timeout, none of our business,
 927            let higher layers handle this.  in fact it's probably an error */
 928         return code;
 929         }
 930
 931     if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
 932         {
 933         BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
 934         return code;
 935         }
 936
 937     state = s->d1;
 938     state->timeout.num_alerts++;
 939     if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
 940         {
 941         /* fail the connection, enough alerts have been sent */
 942         SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED);
 943         return 0;
 944         }
 945
 946     state->timeout.read_timeouts++;
 947     if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
 948         {
 949         send_alert = 1;
 950         state->timeout.read_timeouts = 1;
 951         }
 952
 953
 954 #if 0 /* for now, each alert contains only one record number */
 955     item = pqueue_peek(state->rcvd_records);
 956     if ( item )
 957         {
 958         /* send an alert immediately for all the missing records */
 959         }
 960     else
 961 #endif
 962
 963 #if 0  /* no more alert sending, just retransmit the last set of messages */
 964         if ( send_alert)
 965             ssl3_send_alert(s,SSL3_AL_WARNING,
 966                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
 967 #endif
 968
 969     return dtls1_retransmit_buffered_messages(s) ;
 970     }
 971
 972
 973 static int
 974 dtls1_retransmit_buffered_messages(SSL *s)
 975     {
 976     pqueue sent = s->d1->sent_messages;
 977     piterator iter;
 978     pitem *item;
 979     hm_fragment *frag;
 980     int found = 0;
 981
 982     iter = pqueue_iterator(sent);
 983
 984     for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
 985         {
 986         frag = (hm_fragment *)item->data;
 987         if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 &&
 988             found)
 989             {
 990             fprintf(stderr, "dtls1_retransmit_message() failed\n");
 991             return -1;
 992             }
 993         }
 994
 995     return 1;
 996     }
 997
 998 #if 0
 999 static dtls1_message_buffer *
1000 dtls1_message_buffer_new(unsigned int len)
1001     {
1002     dtls1_message_buffer *msg_buf;
1003
1004     msg_buf = (dtls1_message_buffer *)
1005         OPENSSL_malloc(sizeof(dtls1_message_buffer));
1006     if ( msg_buf == NULL)
1007         return NULL;
1008
1009     memset(msg_buf, 0x00, sizeof(dtls1_message_buffer));
1010
1011     msg_buf->data = (unsigned char *) OPENSSL_malloc(len);
1012     if ( msg_buf->data == NULL)
1013         {
1014         OPENSSL_free(msg_buf);
1015         return NULL;
1016         }
1017
1018     memset(msg_buf->data, 0x00, len);
1019     return msg_buf;
1020     }
1021 #endif
1022
1023 #if 0
1024 static void
1025 dtls1_message_buffer_free(dtls1_message_buffer *msg_buf)
1026     {
1027     if (msg_buf != NULL)
1028         {
1029         OPENSSL_free(msg_buf->data);
1030         OPENSSL_free(msg_buf);
1031         }
1032     }
1033 #endif
1034
1035 int
1036 dtls1_buffer_message(SSL *s, int is_ccs)
1037     {
1038     pitem *item;
1039     hm_fragment *frag;
1040
1041     /* this function is called immediately after a message has
1042      * been serialized */
1043     OPENSSL_assert(s->init_off == 0);
1044
1045     frag = dtls1_hm_fragment_new(s->init_num);
1046
1047     memcpy(frag->fragment, s->init_buf->data, s->init_num);
1048
1049     if ( is_ccs)
1050         {
1051         OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1052             DTLS1_CCS_HEADER_LENGTH == s->init_num);
1053         }
1054     else
1055         {
1056         OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1057             DTLS1_HM_HEADER_LENGTH == s->init_num);
1058         }
1059
1060     frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1061     frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1062     frag->msg_header.type = s->d1->w_msg_hdr.type;
1063     frag->msg_header.frag_off = 0;
1064     frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1065     frag->msg_header.is_ccs = is_ccs;
1066
1067     item = pitem_new(frag->msg_header.seq, frag);
1068     if ( item == NULL)
1069         {
1070         dtls1_hm_fragment_free(frag);
1071         return 0;
1072         }
1073
1074 #if 0
1075     fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1076     fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1077     fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1078 #endif
1079
1080     pqueue_insert(s->d1->sent_messages, item);
1081     return 1;
1082     }
1083
1084 int
1085 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1086     int *found)
1087     {
1088     int ret;
1089     /* XDTLS: for now assuming that read/writes are blocking */
1090     pitem *item;
1091     hm_fragment *frag ;
1092     unsigned long header_length;
1093
1094     /*
1095       OPENSSL_assert(s->init_num == 0);
1096       OPENSSL_assert(s->init_off == 0);
1097      */
1098
1099     /* XDTLS:  the requested message ought to be found, otherwise error */
1100     item = pqueue_find(s->d1->sent_messages, seq);
1101     if ( item == NULL)
1102         {
1103         fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1104         *found = 0;
1105         return 0;
1106         }
1107
1108     *found = 1;
1109     frag = (hm_fragment *)item->data;
1110
1111     if ( frag->msg_header.is_ccs)
1112         header_length = DTLS1_CCS_HEADER_LENGTH;
1113     else
1114         header_length = DTLS1_HM_HEADER_LENGTH;
1115
1116     memcpy(s->init_buf->data, frag->fragment,
1117         frag->msg_header.msg_len + header_length);
1118         s->init_num = frag->msg_header.msg_len + header_length;
1119
1120     dtls1_set_message_header_int(s, frag->msg_header.type,
1121         frag->msg_header.msg_len, frag->msg_header.seq, 0,
1122         frag->msg_header.frag_len);
1123
1124     s->d1->retransmitting = 1;
1125     ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1126         SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1127     s->d1->retransmitting = 0;
1128
1129     BIO_flush(SSL_get_wbio(s));
1130     return ret;
1131     }
1132
1133 /* call this function when the buffered messages are no longer needed */
1134 void
1135 dtls1_clear_record_buffer(SSL *s)
1136     {
1137     pitem *item;
1138
1139     for(item = pqueue_pop(s->d1->sent_messages);
1140         item != NULL; item = pqueue_pop(s->d1->sent_messages))
1141         {
1142         dtls1_hm_fragment_free((hm_fragment *)item->data);
1143         pitem_free(item);
1144         }
1145     }
1146
1147
1148 unsigned char *
1149 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1150     unsigned long len, unsigned long frag_off, unsigned long frag_len)
1151     {
1152     if ( frag_off == 0)
1153         {
1154         s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1155         s->d1->next_handshake_write_seq++;
1156         }
1157
1158     dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1159         frag_off, frag_len);
1160
1161     return p += DTLS1_HM_HEADER_LENGTH;
1162     }
1163
1164
1165 /* don't actually do the writing, wait till the MTU has been retrieved */
1166 static void
1167 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1168     unsigned long len, unsigned short seq_num, unsigned long frag_off,
1169     unsigned long frag_len)
1170     {
1171     struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1172
1173     msg_hdr->type = mt;
1174     msg_hdr->msg_len = len;
1175     msg_hdr->seq = seq_num;
1176     msg_hdr->frag_off = frag_off;
1177     msg_hdr->frag_len = frag_len;
1178 }
1179
1180 static void
1181 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1182         unsigned long frag_len)
1183     {
1184     struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1185
1186     msg_hdr->frag_off = frag_off;
1187     msg_hdr->frag_len = frag_len;
1188     }
1189
1190 static unsigned char *
1191 dtls1_write_message_header(SSL *s, unsigned char *p)
1192     {
1193     struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1194
1195     *p++ = msg_hdr->type;
1196     l2n3(msg_hdr->msg_len, p);
1197
1198     s2n(msg_hdr->seq, p);
1199     l2n3(msg_hdr->frag_off, p);
1200     l2n3(msg_hdr->frag_len, p);
1201
1202     return p;
1203     }
1204
1205 static unsigned int
1206 dtls1_min_mtu(void)
1207     {
1208     return
1209         g_probable_mtu[(sizeof(g_probable_mtu) /
1210            sizeof(g_probable_mtu[0])) - 1];
1211     }
1212
1213 static unsigned int
1214 dtls1_guess_mtu(unsigned int curr_mtu)
1215         {
1216         int i;
1217
1218         if ( curr_mtu == 0 )
1219                 return g_probable_mtu[0] ;
1220
1221         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1222                 if ( curr_mtu > g_probable_mtu[i])
1223                         return g_probable_mtu[i];
1224
1225         return curr_mtu;
1226         }
1227
1228 void
1229 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1230     {
1231     memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1232     msg_hdr->type = *(data++);
1233     n2l3(data, msg_hdr->msg_len);
1234
1235     n2s(data, msg_hdr->seq);
1236     n2l3(data, msg_hdr->frag_off);
1237     n2l3(data, msg_hdr->frag_len);
1238     }
1239
1240 void
1241 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1242     {
1243     memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1244
1245     ccs_hdr->type = *(data++);
1246     n2s(data, ccs_hdr->seq);
1247 }